Dropping an iPhone into a toilet or spilling a glass of water over the device doesn't have to be devastating. While liquid exposure isn't covered under your iPhone warranty, it is not always fatal for your iPhone. Your instinct may be to turn the phone on immediately to see whether it works. Do not do this. Turning on a wet iPhone will cause it to short-circuit, and there's no cure for an iPhone that has short-circuited.
Bag of Rice or Silica
Putting the iPhone in a bag of rice or silica pellets can help dry it out. Put the iPhone in a plastic bag and cover the phone with uncooked rice or packets of silica. Seal it and let it sit for two days. This draws the moisture out of the phone, and, hopefully, returns it to normal operation.
Use a specialized dryer, such as one that works on hearing aids, if you have access to one. If not, use a blow dryer set on low heat and dry the iPhone frequently for one to two hours. Do not set the blow dryer on high heat; plastic parts in the phone could melt.
The slowest way to dry out an iPhone is to let it air dry. Lay the phone on a towel in a dry place and let it dry for at least one week. The faster the iPhone dries, however, the better chance it will have of working correctly. Use the air-dry technique only if the other options are unavailable.
Repair or Replace
If the iPhone still doesn't work, take it to an Apple store for repair or replacement. While warranty doesn't cover liquid damage, Apple may give you a discount on a new iPhone or fix it for a reduced price. A technician can tell if the iPhone has water damage by looking at the liquid submersion indicator on the bottom of the headphone jack. If the circle indicator turns pink, the phone has been damaged by water. Purchase a waterproof case to avoid future accidents if you're frequently near water with your iPhone.